Survey of the vegetation of the habitat Rivers with muddy banks with Chenopodium rubri p.p. and Bidention p.p. vegetation (3270) in Ireland

Tender description

Project background In Ireland, Rivers with muddy banks with Chenopodion rubri p.p. and Bidention p.p. vegetation is primarily found in riverine turloughs where the flood water recedes relatively late and in areas prone to summer flooding. This dynamic habitat is found on damp, fine, mineral soils (typically alluvial muds). Typical species are small, short-lived, fast-growing annuals that are poor competitors. They occupy this habitat because it is exposed for too short a time and too late in the growing season for perennial species to complete their life cycles. The ongoing development of this habitat depends on a continuous supply of fine sediment. This sediment may be derived from external sources or through erosion, suspension and re-deposition of silt within the immediate vicinity of the habitat. Most sites are fed by streams or large underground conduits that supply a significant fine sediment load to the habitat. Wave action can lead to erosion, re-suspension and subsequent deposition of sediment within a basin. O’Connor (2017) revised the typical species reported in NPWS (2013) for the purposes of setting site-specific conservation objectives. This review reduced the typical species list to those that are indicative of good condition in Chenopodion vegetation (positive indicator species) and/or are known to be restricted to or have most occurrences in the habitat (characteristic species). The list was again updated based on the findings and recommendations of Conaghan and Fuller (2018). The full list of typical species list for Rivers with muddy banks with Chenopodion rubri p.p. and Bidention p.p. vegetation (3270) for 2019-2025 is therefore: Callitriche palustrisVU, Chenopodium rubrum (Oxybasis rubra), Gnaphalium uliginosum, Limosella aquatica, Persicaria minor, Rorippa islandica, Alopecurus aequalisNT, Eleocharis acicularis, Riccia cavernosa Other species associated with habitat 3270 include Atriplex prostrata, Rorippa palustris, Persicaria hydropiper, Juncus bufonius and Bidens tripartita. The oc